Browse Articles

Path planning for mobile robots by fusing ant colony optimization and dynamic window approach

To address the problems of low global optimization efficiency and insufficient safety in local obstacle avoidance when mobile robots perform path planning in dynamic and complex environments, this paper proposes a path planning method fusing the ant colony optimization (ACO) and dynamic window approach (DWA), namely the ACO-DWA-DPP algorithm. Firstly, the environment is modeled using a 2D grid map. A potential field force-based heuristic function is introduced to optimize the guidance of path search, and a pheromone reward-punishment strategy and an adaptive evaporation mechanism are designed to improve the algorithm’s convergence speed and global optimization capability. Then, the planned path is subjected to secondary optimization, where redundant turning points are eliminated through connectivity checks to reduce the path length. Secondly, a dynamic collision risk coefficient is incorporated into the dynamic window approach, and the local obstacle avoidance evaluation function is improved to enhance the algorithm’s real-time response capability to dynamic obstacles. Simulation results show that, compared with the traditional ant colony optimization, the improved algorithm reduces the final converged longest path length by 41.26% ~ 48.28%, shortens the shortest path by 10.68% ~ 12.64%, decreases the number of iterations by 83.37% ~ 89.51%, and reduces the number of turning points by 66.94% ~ 81.37%. Moreover, the fused algorithm demonstrates the capability to respond to unknown obstacles in real time within the simulation environment, successfully avoiding them and meeting the requirements for the safe driving of mobile robots. The fused algorithm achieves an effective combination of global path optimization and local dynamic obstacle avoidance, providing a feasible solution for mobile robot path planning in complex scenarios.

Electrical signatures of nitrogen Frenkel pairs in GaN

Deep level transient spectroscopy (DLTS) has been applied to electron-irradiated GaN grown homoepitaxially on highly conductive ammono-GaN substrates. Electron beam energies of 350 and 370 keV were employed, with doses of 12 000 kGy and 1500 or 5000 kGy, respectively. Three electron traps were detected, with concentrations in the range of 1012–1014 cm−3. In addition to the E1 and E3 traps present in as-grown samples, an electron-irradiation-induced peak with a maximum at ∼100 K was observed in the DLTS spectra, consistent with the so-called EE1 trap. EE1 has frequently been associated with a donor level of the nitrogen vacancy {VN (0/+)}. However, the unusual dependence of the EE1 peak magnitude, position, and shape on the filling pulse duration (tp) indicates that the signal does not originate from electron emission from a single level of a simple point defect but instead comprises multiple-level components. We argue that the EE1 DLTS signal in electron-irradiated GaN consists of electron emission contributions from isolated nitrogen vacancies and N-related Frenkel pairs. Furthermore, DLTS analysis reveals a strong electric-field enhancement of the electron emission rate for all components of the signal, consistent with the donor nature of the EE1-related defect levels. The observed DLTS features are attributed to the influence of negatively charged Ni atoms on the electronic properties of VN, with the electron emission and capture rates of electrons by the VN component of the pairs depending on the separation between the pair constituents.

Integrating sentinel-1 SAR and AHP for flood susceptibility and agricultural impact assessment in the Awash River Basin, Ethiopia

Abstract Ethiopia’s economy is highly dependent on agriculture, yet recurring natural hazards continue to expose the country to significant vulnerability. This challenge is particularly severe in the Awash River Basin, where seasonal rainfall frequently triggers widespread flooding, threatening rural livelihoods and food security. Accurate flood monitoring is therefore essential for effective flood risk managment, disaster preparedness and mitigation. Although remote sensing images are widely used for large-scale flood detection, persistent wet-season cloud cover limits optical imagery. Sentinel-1 Synthetic Aperture Radar (SAR), processed in Google Earth Engine (GEE), provides a suitable alternative. However, in the complex terrain of the Awash Basin, conventional threshold-based SAR flood mapping produces substantial errors because terrain effects can be misinterpreted as flood signals. For the 2025 flood event examined in this study, the application of Height Above Nearest Drainage (HAND), Morphology, and SRTM DEM-derived slope masks reduced flood overestimation by an estimated 21.6%, eliminating approximately 199.44 km² of potentially misclassified areas from the initial SAR-derived flood extent and resulting in an estimated inundation area of 923.36 km². SAR-based flood mapping also identified a raw flooded cropland area of 84.62 km², which translates to an error-adjusted cropland exposure of 65.69 ± 7.98 km² with 95% confidence interval (CI). The Analytical Hierarchy Process (AHP) model identifies that the high-risk class covers 51.86% of the basin, while the very high-risk class accounts for 0.61%. To improve flood preparedness, this study integrates diagnostic SAR-based flood observations with a prognostic AHP flood susceptibility model. Spatial analysis shows strong agreement between the two approaches, with 89.25% of the mapped flood extent occurring within areas classified as “High” and “Very High” susceptibility, whereas only 0.25% occurred in low-risk zones, indicating agreement for this event rather than predictive proof. This suggests that the AHP model captures the spatial distribution of flood susceptibility for the studied event. The integrated framework achieves an overall accuracy of 81.5% ± 3.8% (Cohen’s Kappa = 0.630 ± 0.076) with 95% CI. Overall, the findings demonstrate the potential of combining terrain-corrected SAR flood mapping with AHP-based susceptibility assessment for flood risk analysis and climate-resilient planning in data-scarce regions.

An evaluation of a breastfeeding peer support service in North East England: A qualitative study with service users, practitioners and volunteers

Background Breastfeeding has health benefits for women and infants. Although the WHO recommends that infants are breastfed exclusively for the first six months, exclusive breastfeeding rates remain low in the UK, with many women stopping breastfeeding within six weeks of their infant’s birth. Many women face challenges initiating and continuing breastfeeding, including low confidence, limited support and misinformation. Breastfeeding peer support (BPS) services play a vital role in supporting women to continue to breastfeed by connecting new mothers with trained volunteers who offer advice, emotional encouragement and reliable information. Methods This study aimed to undertake a formative evaluation of the BPS service in Newcastle upon Tyne from the perspective of those who deliver the services, the wider healthcare team and mothers’ experiences of utilising the service. This evaluation used a qualitative design, consisting of one-to-one semi-structured interviews with practitioners, volunteers, healthcare professionals and service users. Recruitment took place between 28 th March – 14 th May 2025. Recorded interview data were transcribed verbatim and analysed using Braun and Clarke’s coding reliability thematic analysis. Results Twenty-two interviews were conducted (n = 11 practitioners, volunteers and healthcare professionals and n = 11 service users). Analysis identified four themes: mechanisms of the service; support offered by the service; outcomes of the service, and challenges to service delivery. Overall, the BPS was considered a supportive service by participants. Conclusions The normalisation of breastfeeding was seen as crucial to the service, while service users described that the emotional support provided helped to increase their confidence in breastfeeding. Challenges were identified for the service, including engaging those aged under 25 years and those for whom English is a second language. These findings will be used to inform the future development of the service.

BN Analogue of Butadiyne: A B─B‐Bonded sp–sp Diboron(2) Species and Its Desymmetrization

ABSTRACT In contrast to our earlier contribution on BN analogue of butadiyne featuring a conjugated B≡N─N≡B motif, we report here an alternative and distinct isoelectronic system, Ar*─N≡B─B≡N─Ar* ( 2 ; Ar* = C 6 H 3 ‐2,6‐Trip 2 , Trip = C 6 H 2 ‐2,4,6‐ i Pr 3 ). This B─B‐bonded bis(iminoborane) constitutes an rare example of an sp–sp diboron(2) species. Compound 2 exhibits characteristic mono‐ and double E–H (E = N, O) bond addition across the B≡N units to afford diboron(3) and diborane(4) species, respectively. Notably, mono‐N‐heterocyclic carbene (NHC) coordination induces desymmetrization of the NBBN core, fundamentally altering its electronic structure and reactivity profile. The resulting sp–sp 2 diboron(3) species undergoes a broader range of transformations with DMAB, DABSO, and CO 2 , furnishing novel products through addition, metathesis, and cycloaddition pathways involving selective cleavage of B─B, B≡N, and B═N bonds. Together, these results demonstrate how desymmetrization enables access to distinct reactivity modes within B─B‐bonded bis(iminoborane) frameworks.

Ultrahigh spatial resolution imaging of radiative optical states of single gold nanoantennas by scanning tunneling microscope-induced light emission

Modern nanophotonics allows one to engineer the optical modes and localize light at the nanoscale. In this work, we visualize the local density of optical states (LDOS) distribution of the single femtosecond-laser-printed gold nanobump with ultrahigh spatial resolution. Scanning tunneling microscope-induced light emission allows us to achieve LDOS mapping with a spatial resolution of around 15 nm for single nanobumps and their agglomerates with gold plasmonic nanoantennas, having a relatively small diameter. Our experimental and theoretical results show that a plasmonic nanoantenna can be integrated into an optical system to enhance its radiation outcoupling efficiency, while leaving its modal structure mainly unaffected. A deep understanding of the optical modes in nanostructures opens up possibilities for creating new types of optoelectronic components based on inelastically tunneling electrons, providing light emission.

Catalytic degradation of ciprofloxacin via peroxymonosulfate activation using a UiO66 and amino functionalized silica coated magnetite composite

The effectiveness of a knowledge graph-based lifestyle intervention recommendation system in improving body composition, muscle strength, and physical function in sarcopenic obesity: Study protocol for a randomized controlled trial

Background Sarcopenic obesity (SO) is a complex condition characterized by the coexistence of sarcopenia and obesity, with pathophysiological mechanisms extending beyond the additive effects of either condition alone. Lifestyle intervention is considered an effective management strategy for SO; however, substantial interindividual variability in physiological status and behavioral preferences limits the implementation of personalized intervention. This study aims to evaluate the effectiveness of a knowledge graph-based lifestyle recommendation system in improving skeletal muscle mass and related outcomes in patients with SO. Methods This randomized controlled trial will recruit 208 patients with SO, who will be randomly assigned in a 1:1 ratio to an intervention or control group. In addition to routine lifestyle guidance, the intervention group will receive a 24-week personalized intervention delivered through the Sarcopenic Obesity-Knowledge Graph Care System (SO-KGCS), whereas the control group will receive routine health education and lifestyle advice only. The intervention period is defined as the 24-week intervention period from baseline to week 24. The primary outcome measure is skeletal muscle mass. Secondary outcome measures include grip strength, skeletal muscle mass index, body fat percentage, physical function, and quality of life. Outcomes will be assessed at baseline before randomization and at weeks 8, 16, and 24 during the 24-week intervention period. The intervention will end at week 24, after which participants will enter a 24-week post-intervention follow-up period without systematic intervention. Follow-up outcome data will be collected at week 48. Discussion This study will evaluate the effectiveness of a knowledge graph-based recommendation system in enhancing body composition, muscle strength, physical function, and quality of life in patients with SO. If effective, the SO-KGCS may provide a feasible intelligent approach for personalized chronic disease management. Trial registration ChiCTR, ChiCTR2500111882.

Outside Front Cover: Meso‐Strap Engineering of Aromaticity Redistribution in Porphyrinoids (Angew. Chem. Int. Ed. 31/2026)

Single-atom sensor for low-frequency electric field

Precision measurement of low-frequency electric field (LFEF) signals with frequency from 30 to 300 kHz is crucial for advancing both fundamental science and practical applications owing to their unique frequency regime. For conventional electromagnetic antennas, the long wavelength (i.e., several kilometers) of the LFEF leads to a severe size constraint because efficient radiation becomes challenging to achieve when the antenna size is much smaller than the long wavelength of the LFEF signals, which in turn results in a reduction of measurement sensitivity and compromises antenna's performance. By exploiting the high intrinsic sensitivity of cold trapped ions to weak alternating electric signals via Coulomb interaction, we demonstrate a single-ion phonon laser sensor based on an injection-locked 40Ca+ ion confined in a surface-electrode trap. Combining the beat frequency technique with the injection-locked phonon laser oscillation, we demonstrate a practical and efficient approach for simultaneous extraction of the frequency, phase, and amplitude from a single measurement, without the need for sideband cooling. This approach achieves precision detection for LFEF signals with a sensitivity of 403.8 μV/(m Hz1/2) and a detection limit of 61.5 μV/m. In addition, this approach also shows remarkable robustness against noise. Our study helps realize practical single-atom sensors in the low-frequency regime, opening avenues for applications in subsurface communication, precision metrology, mass spectrometry, and biomedical monitoring.

High intragenotypic diversity, serogroup heterogeneity, and recombination of African swine fever virus strains circulating in sylvatic and domestic hosts

Understanding the underuse: Barriers to vacuum-assisted birth among clinicians in Tanzania: An exploratory qualitative study

Background Vacuum-assisted birth (VAB) is a critical obstetric intervention for saving the lives of the mothers and newborns, particularly in cases of prolonged second-stage labor, maternal exhaustion, or fetal distress. Despite its proven benefits, VAB remains underutilized, contributing to an increased rate of unnecessary cesarean sections, some of which could be avoided with timely vacuum extraction. This study aimed to explore the barriers to the use of VAB among clinicians at a tertiary hospital in Tanzania. Materials and Methods An exploratory qualitative study using in-depth interviews (IDIs) was employed. Twelve clinicians with relevant experience in vacuum-assisted birth were recruited purposively into the study. A semi-structured IDI guide was used to facilitate the interviews. Data were analyzed inductively using thematic analysis to identify key patterns and categories related to barriers in the use of VAB. Results Organizational and individual barriers were identified as key challenges to the use of VAB. Organizational barriers included insufficient availability of VAB equipment, ineffectiveness of the available devices, and poor team dynamics that hindered collaborative decision-making regarding VAB use. Individual barriers centered on clinicians’ apprehension about potential adverse outcomes, along with limited skills and practical experience in performing VAB procedures. Conclusion The utilization of VAB by clinicians is hindered by both organizational and individual barriers. Addressing these challenges through improved availability of functional equipment, enhanced training to build clinicians’ skills, and improving working conditions has the potential to increase the use of VAB. Strengthening these areas could help reduce the rate of unnecessary caesarean deliveries.

Meso‐Strap Engineering of Aromaticity Redistribution in Porphyrinoids

ABSTRACT Porphyrins possess one of the most robust aromatic circuits in chemistry, and even highly distorted derivatives preserve the intrinsic [18]π aromatic framework. Here we demonstrate that meso ‐strap engineering can override this intrinsic stability and induce controllable aromaticity redistribution within porphyrinoid networks. Systematic installation of tripyrrin‐, 1,8‐dipyrrylcarbazole‐, and tetrapyrrolic straps reveals that short straps impose severe geometric strain that collapses the central [18] porphyrin aromatic circuit, generating alternative aromatic subunits or nonaromatic cores. In contrast, elongation to a tetrapyrrolic linker preserves the porphyrin aromaticity even in doubly bridged architectures. Structural, spectroscopic, and computational analyses collectively reveal that the intrinsic balance between strain energy and aromatic stabilization governs the fate of conjugation in these systems. These findings establish meso ‐strap engineering as a predictive design principle for controlling aromaticity redistribution in porphyrinoids and related π‐conjugated macrocycles.

Wavelength-dependent C8-BTBT/C60 heterojunction transistor array for optical communication and image recognition functions

Organic optoelectronic transistors are promising for artificial vision systems, thanks to their excellent optical properties and facile processability. However, low charge transport efficiency and narrow photoresponse remain critical challenges. Here, an interface-engineered organic C8-BTBT/C60 heterojunction is proposed as an efficient active channel for multifunctional phototransistor applications, where the introduction of a C60 insertion layer forms a well-defined donor–acceptor interface that enhances charge transport, promotes efficient photogenerated charge separation, and broadens the spectral response. The device exhibits polarization-sensitive photodetection with a significant dichroic ratio of 2.71 and synaptic behaviors including short-term memory, long-term memory, and consolidated memory. More importantly, a large-scale device array is demonstrated for the real-time image perception and denoising functionality. Finally, an artificial visual system is proved by using such a device array with a convolutional neural network, significantly improving the image recognition accuracy from 73% to 93%. This work provides a promising approach toward future intelligent vision systems with efficient visual information processing.

Global transmission pathways and adaptive molecular evolution of avian infectious bronchitis GI-23 (Variant 2)

Abstract The infectious bronchitis virus (IBV) causes significant losses in commercial poultry egg and meat production. Since its first emergence, the genotype GI-23 (Variant 2) has progressively increased its geographical distribution, shown a significant virulence, and challenged the vaccine efficacy. Global viral transmission could be attributed to multiple factors including human related activities such as poultry and vaccine trades while other contributing factors such as the role of wild birds cannot be neglected. Therefore, A total 260 full S1 GI-23 sequences were obtained from Genebank, structured and intensively analyzed. The recombination analyses were conducted using RDP5 and GARD on the total dataset to identify the possible recombinant events. The recombinant-free dataset (214 sequences) was phylogeographically analyzed using BEAST 1.10, then selection pressure analyses to identify the possible migration routes and selection pressure markers, respectively. Recombination analyses showed multiple internal recombination events in 17.6% of the sequences. Phylogeographic analysis suggested Central and Eastern European (CEE) countries (i.e., particularly Poland and Romania) as likely sources of American GI-23-like virus outbreaks. Interestingly, the selection pressure analyses indicated positive selection signals, identifying five codons in some previously distinguished critical positions such as 61, 94, 119, 127, and 197. The virus extended geographical spread as well as molecular evolution through recombination and positive selection in the spike gene poses a major concern for increased adaptation and enhanced pathogenicity in susceptible domesticated and probably wild birds. Further studies on the impact of both recombination events and the identified positive selection codons are highly recommended to elucidate the molecular evolution mechanisms of IBV GI-23.

Pilot study: The effect of eight weeks of aerobic training in the two phases of light and dark circadian rhythm on genes (OCT4, NANOG, SOX2, REX1) in bone tissue of diabetic mice

Introduction Diabetes mellitus impairs bone metabolism through chronic hyperglycemia, oxidative stress, and inflammation, leading to reduced osteoblast activity and downregulation of key pluripotency genes such as Octamer-binding transcription factor 4 (OCT4), Nanog homeobox (NANOG), SRY-box transcription factor 2 (SOX2), and Reduced expression protein 1 (REX1).The present study investigated whether the timing of aerobic exercise (morning vs. evening) influences the expression of pluripotency genes in the bone tissue of diabetic mice. Methods Eighteen male NMRI mice were assigned to healthy control, diabetic control, or diabetic exercise groups. Diabetes was induced using a high-fat diet combined with low-dose streptozotocin. Aerobic training was performed for eight weeks at either ZT3 (morning) or ZT15 (evening), five sessions per week, at 50–60% Vmax. Blood glucose, insulin, HOMA-IR, and maximum running speed were assessed, and gene expression in bone tissue was measured using qRT-PCR. Data were analyzed using one-way ANOVA with Tukey post hoc testing (p < 0.05). Results Diabetic mice exhibited significant increases in glucose, insulin, and HOMA-IR, along with marked reductions in pluripotency gene expression, particularly at ZT3. Aerobic exercise significantly improved metabolic parameters and partially restored gene expression, with the greatest enhancement observed at ZT15. SOX2 and REX1 showed the most robust recovery under evening training conditions. Conclusion The findings indicate that circadian timing modulates the beneficial effects of aerobic exercise on pluripotency gene expression in diabetic bone tissue. Evening exercise (ZT15) exerts superior restorative effects, suggesting that chronobiology aligned training may serve as an effective strategy for improving bone regenerative potential in diabetes.

Efficient sub-bandgap excitation in near-infrared luminescence of modulation-doped InAs quantum dot system

This study investigates highly efficient sub-bandgap excitation and roles of donor–acceptor (D–A) pairs in Si modulation-doped InAs/GaAs quantum dot (QD) systems with low-temperature variable-excitation wavelength photoluminescence (PL) spectroscopy. Such a D–A pair is tentatively assigned to a pair of Si donor and C acceptor with the PL emission at 831.5 nm. It is shown that the resonant excitation of this D–A pair can significantly enhance the near-infrared emission of the InAs QDs, yielding a PL intensity comparable to that under near-band edge excitation. The modulation doping of Si is found to make the D–A pair be in the D+–A− state, which enables efficient sub-bandgap optical excitation. Owing to the proximity (5 nm) between the doped Si donor layers and the QD layers, the D–A pairs strongly couple with both the QDs and GaAs barriers, leading to direct carrier transfer from the excited D–A pairs to QDs and therefore enhanced QD emission. This work reveals the impact of D–A pairs on carrier interactions in the InAs/GaAs QD systems and demonstrates an efficient strategy to engineer carrier interactions by spatial modulation of donor/acceptor dopants in semiconductor quantum structures.

Asymmetric deformation law and differentiated control technique for the roadway of an isolated working face in an extra-thick coal seam

Impact of semaglutide withdrawal on cardiometabolic profile and physiology of energy balance: Recovery effects after semaglutide termination – The REST trial study protocol

Background Glucagon-like peptide-1 (GLP-1) receptor agonists such as semaglutide have been shown to induce substantial weight loss and improve cardiometabolic risk factors in patients living with obesity. However, most individuals regain weight after abrupt withdrawal of semaglutide, with reversal of its beneficial cardiometabolic effects. Methods We propose a randomized controlled trial to determine whether a gradual dose reduction of semaglutide prior to complete discontinuation is associated with differential changes in weight and cardiometabolic profile as compared to immediate treatment cessation. Individuals living with obesity without preexisting cardiovascular disease who are receiving semaglutide for weight management and have achieved prior weight reduction of at least 10% with no further weight loss over past 12 weeks will be randomized to either gradual dose reduction over 16 weeks or abrupt treatment discontinuation. The primary outcome will be the difference in body weight change (%) between the study groups. Secondary outcomes will include 24-hour ambulatory blood pressure and fasting ghrelin levels. Discussion We hypothesize that gradual reduction of semaglutide will be associated with less weight regain and cardiometabolic deterioration compared with immediate cessation. This study addresses an important real-world problem regarding treatment discontinuation strategies and may inform future approaches for long-term obesity management. Trial registration NCT07294950 (ClinicalTrials.gov).

Temperature effect on the dispersion of spin waves in the ferromagnetic thin film with Dzyaloshinskii–Moriya interaction

Ferromagnetic thin films are one of the promising platforms for developing spintronic devices due to the multi-field-controlled diverse dynamic behaviors of spin waves and magnetization topologies like skyrmions. Especially, the short-wavelength spin wave is an excellent information carrier because of the absence of Joule heat and high-speed propagation. However, although the control of spin waves by magnetic field and their interactions is widely studied, the temperature effect on spin waves as a natural feature is still unclear. Here, we demonstrated that the dispersion relations of spin waves in both the out-of-plane and in-plane directions are highly dependent on the temperature by employing a temperature-related phase-field method based on Ginzburg–Landau theory. By combining analytical and numerical results, we proposed a dispersion relation that reveals temperature-dependent spin wave stiffness, energy gap, and so on. We not only elucidate the temperature effect on spin waves from the perspectives of thermodynamics and micromagnetic dynamics but also provide the relevant equations. These findings should serve as a valuable theoretical guide for future investigations into magnetization dynamics and the development of spintronic devices.